How to perform basic tasks in Cycles vs. Blender Internal?
Introduction to Nodes

Well, you can have all sort of nodes, mostly it's quite strait forward what the node does, for an instance the Transparency node or the diffuse, glass, glossy or emission node. Depending on what you want to make you might want to Mix two nodes, for that you would use a Mix Shader node or an Add Shader node, the difference is that the Mix Shader node has a more controll over the Factor that the two nodes are displayed. I'll give some examples of how you can do basic things with nodes.


Giving material an Image Texture

To give a material an Image Texture you would create a Diffuse Node then connect to it the Image Texture Node and plug the Diffuse Node in to the Surface slot in the Material Output Node.





Giving material a normal map

There are couple of ways that you can give your material a Normal Map but a common one would be by simply connecting a Normal Map node into the Normal slot  of the Diffuse Node, also for Normal Map to work properly you have to plug into the Color slot of the Normal Map node another Image Texture Node, this Image Texture would be your Normal Map.





Adding Decals to your material


Adding Decals to your model is slightly more difficult, to add a Decal to your material you would need to connect MixRGB Node into the Diffuse Node, then you will have to connect your Base Texture into the bottom slot and the Decal Image Texture into the upper slot of the MixRGB and finally use the Alpha value as the factor for them both, just like so: